1. Technical Field
The present invention relates to a movable contact element used for operating various electronic apparatuses and a switch using the same.
2. Background Art
Recently, a variety of high-performance electronic apparatuses such as mobile phones or car navigation systems are being developed. With the development of electronic apparatuses, there is demand for a device which can perform various operations on a movable contact element used for operating the electronic apparatuses or a switch.
Such a conventional movable contact element and a switch using the same will be described with reference to FIG. 15.
FIG. 15 is a cross-sectional view of conventional switch 150. In FIG. 15, switch 150 has movable contact element 104, substrate 105, and fixed contacts 106. Movable contact element 104 has cover sheet 101 and movable contacts 102. Cover sheet 101 with flexibility is formed in a film shape. Each of movable contacts 102 is formed in substantially a dome shape and is made of a conductive thin metal plate. The plurality of movable contacts 102 are bonded to the lower surface of cover sheet 101 by using adhesive 103, thereby forming movable contact element 104.
Substrate 105 has a plurality of wiring patterns (not shown) formed on a top surface and a lower surface thereof. Each of fixed contacts 106 is composed of central fixed contact 106A (hereinafter, referred to as contact 106A) and outer fixed contact 106B (hereinafter, referred to as contact 106B). Contact 106A has a circular shape and is formed on a top surface of substrate 105. Contact 106B has a horseshoe shape and is formed on the top surface of substrate 105 so as to surround contact 106A. As such, the plurality of fixed contacts 106 are provided on the top surface of substrate 105.
Cover sheet 101 is bonded to the top surface of substrate 105, and the outer periphery of movable contact 102 is loaded on contact 106B. Further, the central portion of the lower surface of movable contact 102 is disposed to face contact 106A with a predetermined gap therebetween. In such a manner, switch 150 is constructed.
Switch 150 constructed in such a manner is mounted on an operating portion of an electronic apparatus (not shown), and an operation body (not shown) is disposed above switch 150 so as to move up and down or swing. Further, the plurality of fixed contacts 106 are connected to an electronic circuit (not shown) of the electronic apparatus through the wiring patterns.
In such a construction, the operation body is pressed or swung. Then, the lower surface of the pressed or swung operation body presses a top surface of cover sheet 101. When the top surface of cover sheet 101 is pressed, cover sheet 101 is bent. Further, the dome-shaped central portion of movable contact 102 is pressed. When a predetermined pressing force is applied to movable contact 102, movable contact 102 is elastically inverted downward with a click feeling such that a central portion of a lower surface of movable contact 102 comes in contact with contact 106A. Accordingly, contact 106A and contact 106B are electrically connected to each other through movable contact 102.
When the pressing force applied to the operation body is released, movable contact 102 elastically restores upward by an elastic restoring force of movable contact 102, and the central portion of the lower surface of movable contact 102 is separated from contact 106A. Accordingly, the electrical connection between contact 106A and contact 106B is cut off.
The electronic circuit of the electronic apparatus detects the electrical connection and disconnection among the plurality of fixed contacts 106. For example, when the operation body is operated upward in a state where a plurality of menus are displayed on a display screen (not shown) such as a liquid crystal display element of an electronic apparatus, a cursor or pointer displayed on the display screen is moved upward by a predetermined distance.
Further, when the operation body is operated in the right direction, the electronic circuit detects the electrical connection and disconnection of fixed contact 106 positioned in the vicinity of the operated operation body. Then, the cursor or pointer displayed on the display screen is moved in the right direction by a predetermined distance.
That is, as the operation body is pressed or swung, movable contact 102 under the operated operation body is elastically inverted, and the electrical connection and disconnection of fixed contacts 106 is performed. Further, the electronic circuit of the electronic apparatus detects at which place the electrical connection and disconnection of fixed contacts 106 is performed. Accordingly, the operation or switching of functions of the electronic apparatus is performed in accordance with the operation of the operation body.
Such conventional switch 150 is disclosed in Japanese Patent Unexamined Publication No. 2003-123596, for example.
However, in conventional movable contact element 104 and switch 150 using the same, a large number of movable contacts 102 and fixed contacts 106 are needed to execute various operations. Further, an operation body having a complicated shape is also required. Therefore, the number of parts composing switch 150 increases, and the construction of switch 150 becomes complicated. As a result, movable contact 102 and switch 150 become expensive.